Drive for in-slot winding machine

ABSTRACT

A mechanical drive arrangement is disclosed for converting rotary motion of one shaft into a combined rotary and axial motion of a second shaft, the latter motion being particularly useful in an automatic stator in-slot winding machine. The drive arrangement has first and second non-circular gears constrained to rotate about fixed axes, a source of energy rotatably driving one of those axes or shafts, and a third gear rotatable about a movable axis and adapted to mesh with each of the first and second gears, the third gear axis being movable parallel to itself in a plane, and a ball and socket linkage between an eccentric point on the third gear and the driven shaft.

[ 51 July 25, 1972 3,433,421 3/1969Moore.......................................74/23 2,552,572 5/l95l...74/437 Primary Examiner-Milton Kaufman Assistant Examiner-Wesley S.Ratliff, Jr. Attorney-letters and Rickert [57] ABSTRACT A mechanicaldrive arrangement is disclosed for converting rotary motion of one shaftinto a combined rotary and axial motion of a second shaft, the lattermotion being particularly useful in an automatic stator in-slot windingmachine. The drive arrangement has first and second non-circular geursconstrained to rotate about fixed axes. a source of energy rotatablydriving one of those axes or shafts, and a third gear rotatable about amovable axis and adapted to mesh with each of the first and secondgears, the third gear axis being movable .74/23, 74/437, 242/l.l R..'..Fl6h 21/00 .74/23, 437; 242/l.l R

MACHINE [72] Inventor: Eugene E. Geber, Ossian, Ind.

[73] Industra Products, Inc., Ft. Wayne, Ind.

Sept. 30, 1970 References Cited UNITED STATES PATENTS Assignee:

en 8 mm rl .md He um n ma .l mm m ag u d mu m h 2. t a .m h W m m a ,m De 6 mm P 3C 1 n C .IM 2 Km 1 C Be i ma n l.

e "6%?" a mam pbS WNB MMM 447M M u 44 22 Weis nu n e hwmm a CPME 98005 4666 99999 flfl WW484 4096 43884 47273 Patented July 25, 1972 3Sheets-Sheet l R Kw R B 0 E MN NF- R w m mm T E A G Y m B Patented July25, 1972 3,678,766

3 Sheets-Sheet 2 F I G 3 INVENTOR EUGENE E. GEBER ATTORNEYS PatentedJuly 25, 1972 3 Sheets-Sheet 5 INVENTOR EUGENE E. GEBER BY%M w A TORNEYSDRIVE FOR IN-SLOT WINDING MACHINE CROSS REFERENCETO RELATED APPLICATIONSThe present application has utility as a mechanical drive linkage forthe winding needle in an in-slot stator winding operation particularlyfor shaded pole stators and has been particularly useful in conjunctionwith applicants copending application entitled Automatic Tooling ForIn-Slot Winder" filed Sept. 30, 1970 and bearing Ser. No. 76,862 andassigned to the assignee of the present invention.

BACKGROUND OF THE INVENTION automatic coil winding machine to effectin-slot winding of a coil in a stator.

The winding head or needle which dispenses the wire in such an in-slotwinding operation must execute a substantially linear motion as itpasses along one of the slots in the stator and then as it emerges fromthat stator slot must execute a somewhat semi-circular motion to arriveat another stator slot through which it must pass in the oppositedirection in again a linear motion. When it emerges from this secondslot another somewhat semi-circular motion is required to get back tothe original slot and complete one turn of the coil. After numerousidentical passes that particular coil is complete and the winding heador needle may move on to wind another coil within the same stator. Theprior art is also aware of multiple needle winding heads which maysimultaneously wind two or four coils within a given stator.

Numerous schemes are known in the prior art for effecting this complexwinding motion, thus for example, the US. Pat. to Mason No. 2,934,280 asbest seen in FIG. 7 has a cylindrical shell provided with a slot inwhich a follower is constrained to move. Such a structure will, ofcourse, give the desired motion, however, the friction between thefollower and the motion defining slot may be large and slight amounts ofwear in that slot or on the follower soon cause the winding needle toexecute erratic motion and the maintenance problems with such astructure are substantial. A somewhat similar device having a slot onthe exterior of a rotating drum and a follower which rides in that slotis disclosed in the patent to Nill et a]. US Pat. No. 3,025,008 andsuffers from basically the same defects as the Mason scheme. Anotherapproach for providing this in-slot winding motion is illustrated in theU.S. Pat. to Ebbert No. 3,276,275 which as illustrated in his FIG. 3relies on a ball and socket joint wherein the socket has a peculiar andhard to manufacture configuration. All of these prior art schemes forachieving an in-slot winding motion are complicated, expensive tomanufacture and require extremely close tolerances which are soonexceeded due to wear.

SUMMARY OF THE INVENTION The foregoing prior art problems are overcomeby the present invention which has a pair of noncircular gears rotatingabout fixed axes one of which is driven by the power source and betweenwhich a third gear rotating about a movable axis migrates in a plane.This third gear either directly or indirectly communicates its motion byan eccentrically located ball and socket joint to the shaft carrying thewinding needle.

Accordingly it is one object of the present invention to provide adevice for achieving an in-slot winding motion.

It is another object of the present invention to provide a mechanicaldrive arrangement for converting rotary motion of one shaft into acombined rotary and axial motion of a second shaft.

It is a further object of the present invention to provide a drivemechanism for an in-slot coil winding machine which is durable andvirtually maintenance free.

These and other objects and advantages of the present invention willbecome more apparent from the following detailed disclosure read inconjunction with the accompanying drawing in which:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of themoving parts of the drive arrangement of the present invention;

FIG. 2 is a horizontal section illustrating the non-circular gearsemployed in one embodiment of the present invention;

FIG. 3 is a top view of the structure of FIG. 1;

FIG. 4 is a horizontal section similar to FIG. 2 but employing gears ofa different and improved configuration;

FIG. 5 is a plane projection of the motion executed by the winding headusing the gears of FIG. 2; and

FIG. 6 is a plane projection showing the winding head motion using thegears of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning first to FIG. 1, energyis supplied to the drive arrangement of the present invention in theform of rotary motion by a pulley 11 which would be driven by a V beltconnected to a primary source of power. The pulley ll drives the shaftor axis 13 which in turn is directly coupled to the gear 15. The gear 15and the matched free running gear 17 are both of a non-circularconfiguration and both rotate about an axis located at other than thegeometrical center of these noncircular gears. A third gear 19 which inthe preferred embodiment is circular but could also be noncircularmeshes at all times with the two gears 15 and I7 and rotates about anaxis 21 which is movable parallel to itself so as to always lie in aplane. This plane motion of the axis 211 of the gear is achieved byproviding a support block 23 which is slidable linearly along the rods25 and 26. Thus, the axis of the gear 19 migrates according to theparticular rotational orientation of the two gears 15 and 17. Aneccentric point on the gear 19, that is some point off of the axis 21,is provided with a ball socket 27 or 27' which executes a circularmotion relative to the shaft or axis 21 at the same time that this axisis migrating in a plane. A second shaft 29 provided with a lower bronzebushing 31 and an upper bronze bushing (not shown) is inherently free toboth rotate and slide axially but is coupled to the ball socket 27 by aball 33 which is rigidly attached to the shaft 29 by a connecting arm35. The: shaft 29 is hollow and provided at its upper end with a windinghead or needle 37 so that wire 39 may be fed up through the shaft andout through the winding needle for an in-slot winding operation.

The motion executed by the center of the ball 33 will determine themotion of the winding needle 37 if variations in the length of theconnecting arm 35 are taken into account. Assume first that the axis 21has migrated to its rightmost position as shown in FIG. 1. At this timethe center of the ball 33 will lie in the plane of migration of theshaft 21. As the gear 15 rotates in a clockwise direction two thingshappen, first the gear 19 begins rotating in a counterclockwisedirection which by itself will cause the center of the ball 33 to begina downward motion coupled with motion somewhat to the right. However,the gear 15 is not circular and it also begins to push the shaft 21toward the left, an amount just enough to compensate for the rightwardmotion imparted by pure rotation of the gear 19. The result of these twocombined effects is a mo tion of the center of the ball 33 directlydownward rather than to the left or right. This portion of the motion ofcourse corresponds to the time when the needle 37 is passing downwardlyin one slot of a stator. A similar result of course occurs when the axisor shaft 21 is near its leftmost migration. Thus, while an eccentricpoint such as represented by the ball socket 27 would normally execute acircular motion about its shaft 21, allowing this shaft to migrate asdetermined by the configuration of the pair of noncircular gears 15 and17 tends to flatten out the two sides of this circular motion and causethem to be approximately straight lines to allow the needle 37 toexecute linear motion while it is inside one of the stator slots. Thus,the actual motion imparted to the center of the ball 33 and to thewinding needle 37 is substantially that shown in FIGS. 8, 9 and of theaforementioned Ebbert patent.

The ball socket 27 or 27' must of course be cylindrical rather thanspherical so as to allow the ball 33 to be positioned more deeply in thesocket at the uppermost and lowermost positions of the shaft 29. Thesocket 27 is also an eccentric point relative to the gear 19 however,the distance from the axis 21 to the socket 27' is less than thedistance from the axis 21 to the socket 27. Placing the ball 33 in thesocket 27 without changing the length of the connecting arm 35 will ofcourse diminish the extent of axial motion of the shaft 29. Similarly,changing the length of the connecting arm 35 for a given distance fromthe socket to the axis 21 will substantially change the extent of rotarymotion of the shaft 29. These two possible adjustments are somewhatinterrelated and some care must be taken in selecting the propereccentric point and proper connecting arm length.

Numerous possible modifications are apparent on the face of FIG. 1, thusthe noncircular gears and 17 may be provided with counter weights 40 and41 so that no imbalance impairs the high speed running of this drivearrangement. Similarly, cams having the same general configuration asthe respective gear to which they are attached may be provided so thatthe laterial forces which must be exerted on the gear 19 are actuallyexerted on mating cam surfaces such as 43 and 45 rather than on the gearteeth. Such cams will substantially diminish the wear experienced by thegears in this drive arrangement thus prolonging life and diminishingmaintenance problems. Similarly, it should be apparent that therotational .motion experienced by the shaft 29 is limited and if it weredesired to impart a full 180 rotation to this shaft, a gearingarrangement such as illustrated in FIG. 3 of the aforementioned Ebbertpatent would be desirable. Such a gearing arrangement or other schemewould be necessary for example in winding the coils for a two polemachine. Such a gearing arrangement could also be obviously used to varythe extent of rotational movement imparted to the shaft 29 in order toarrive in any desired combination of rotational and axial motion.

The specific gear configuration illustrated in FIG. 2 shows the gear 19as being a circular gear rotating about the center of that circle whilethe gears 15 and 17 are identical off center noncircular gears both ofwhich are at their extreme leftmost or extreme rightmost positionsimultaneously. It should be obvious that varying the configuration ofthe two gears 15 and 17 will result in varying the combined axial androtational motion of the shaft 29 and indeed by the proper choice ofgears most any desired combination of motions might be achieved. Thespecific configuration illustrated in FIG. 2 imparted to an eccentricpoint on the gear 19 the motion illustrated as a plane projection inFIG. 5 whereas the configuration illustrated in FIG. 4 wherein thecenter gear 19' rotates about a point other than its center gave thedesired motion illustrated as a plane projection in FIG. 6. As an aid tothe reader, the gear configuration shown in FIG. 4 is drawn to scale.

Numerous modifications will suggest themselves to those of ordinaryskill in the art and accordingly the scope of the present invention isto be measured only by that of the appended claims.

Iclaim:

1. A mechanical drive arrangement for converting rotary motion ofparallel shafts in a plane into a combined rotary and axial motion of aperpendicular shaft comprising:

first and second noncircular gears constrained to rotate about fixedaxes;

a third gear rotatable on one of said parallel shafts about a movableaxis and in mesh with each of said first and second ears; means forlmrting the motion of said third gear axis to motion in the plane ofsaid parallel shafts; and

means connecting said perpendicular shaft to said third gear.

2. The drive of claim 1 wherein said third gear is circular.

3. The drive of claim 1 wherein said connecting means comprises:

a ball socket attached to said third gear shaft at a point off saidmovable axis, and a connecting arm extending from said perpendicularshaft and having a ball at the remote end of the am adapted to fitwithin the socket.

4. The drive of claim 1 wherein said one shaft is directly coupled todrive said first gear.

5. The drive of claim 1 further comprising means for varying the extentof axial motion of said second shaft.

6. The drive of claim 3 further comprising means for varying the extentof rotary motion of said second shaft.

7. The drive of claim 5 wherein said means for varying comprises meansfor changing the distance between said eccentric point and said thirdgear axis.

8. The drive of claim 6 wherein said means for varying comprises meansfor changing the length of said connecting arm.

9. The drive of claim 3 wherein said perpendicular shaft is providedwith a needle adapted to dispense wire in an in-slot winding operation,said needle extending from said perpendicular shaft in a directionperpendicular to said second shaft.

10. The drive of claim 1 wherein said perpendicular shaft is providedwith a needle adapted to dispense wire in an in-slot coil windingoperation.

11. The drive of claim 1 wherein each of said first, second and thirdgears is provided with mating cam surfaces for diminishing the wearexperienced by the respective gear.

12. A mechanical drive arrangement for converting rotary motion of oneshaft into rotary and axial motion of a second shaft comprising:

a non-circular gear constrained to rotate about a fixed axis of said oneshaft;

a movable gear rotatable about a movable shaft and in mesh with saidnon-circular gear;

means for limiting the motion of said movable gear to plane parallelmotion of its shaft;

means for urging said movable gear to mesh with said noncircular gear;and

means connecting said second shaft to said movable gear at a pointremoved from the shaft of said movable gear.

1. A mechanical drive arrangement for converting rotary motion of parallel shafts in a plane into a combined rotary and axial motion of a perpendicular shaft comprising: first and second noncircular gears constrained to rotate about fixed axes; a third gear rotatable on one of said parallel shafts about a movable axis and in mesh with each of said first and second gears; means for limiting the motion of said third gear axis to motion in the plane of said parallel shafts; and means connecting said perpendicular shaft to said third gear.
 2. The drive of claim 1 wherein said third gear is circular.
 3. The drive of claim 1 wherein said connecting means comprises: a ball socket attached to said third gear shaft at a point off said movable axis, and a connecting arm extending from said perpendicular shaft and having a ball at the remote end of the arm adapted to fit within the socket.
 4. The drive of claim 1 wherein said one shaft is directly coupled to drive said first gear.
 5. The drive of claim 1 further comprising means for varying the extent of axial motion of said second shaft.
 6. The drive of claim 3 further comprising means for varying the extent of rotary motion of said second shaft.
 7. The drive of claim 5 wherein said means for varying comprises means for changing the distance between said eccentric point and said third gear axis.
 8. The drive of claim 6 wherein said means for varying comprises means for changing the length of said connecting arm.
 9. The drive of claim 3 wherein said perpendicular shaft is provided with a needle adapted to dispense wire in an in-slot winding operation, said needle extending from said perpendicular shaft in a direction perpendicular to said second shaft.
 10. The drive of claim 1 wherein said perpendicular shaft is provided with a needle adapted to dispense wire in an in-slot coil winding operation.
 11. The drive of claim 1 wherein each of said first, second and third gears is provided with mating cam surfaces for diminishing the wear experienced by the respective gear.
 12. A mechanical drive arrangement for converting rotary motion of one shaft into rotary and axial motion of a second shaft comprising: a non-circular gear constrained to rotate about a fixed axis of said one shaft; a movable gear rotatable about a movable shaft and in mesh with said non-circular gear; means for limiting the motion of said movable gear to plane parallel motion of its shaft; means for urging said movable gear to mesh with said non-circular gear; and means connecting said second shaft to said movable gear at a point removed from the shaft of said movable gear. 